Today, when voice, data or video communication signals are transmitted from one location to another the chances are high that such communications will be sent via an optical fiber network. So-called “ultra, long-reach” (“ULR”) optical fiber networks are in the planning stages or just being built. ULR networks are characterized by their ability to transmit signals extremely long distances without the need to process the signals other than simple amplification.
The advantages offered by ULR networks are many. First, signals within links of a ULR network can go extremely long distances without being processed. The fewer times a signal needs to be processed, the less expensive the link will be when built and operated.
Because processing is not needed to be done as often, it is possible to process signals from multiple links using the same processing equipment.
Unfortunately, the advantages offered by ULR networks have not been realized because the design of so-called electronic “cross-connection” equipment has not evolved to take these advantages into consideration. For example, existing electronic cross-connection designs still require that an individual processing unit (e.g., an optical-to-electrical-to-optical (“OEO”) regenerator) be dedicated to each wavelength within a link. This is a potential waste of resources because signals within a ULR link may not need to be processed at all at any given “node.”
Utilizing existing electronic cross-connection equipment to process signals from ULR links has other inherent drawbacks. When OEOs are used, it means the optical network is not “transparent”. That is, the transmitters and receivers used in such a network must be capable of sending and receiving signals compatible with one or more specific electrical/electronic-based “protocols”. Only signals formatted to fit such protocols will “pass through” the network. In contrast, when OEOs are not used the network remains transparent; capable of passing any number of optical signals regardless, for the most part, of the protocol or bit rate used.
It follows, then, that it makes little sense to utilize existing cross-connection designs to process signals from a ULR link when such processing is not needed and when such processing converts a transparent ULR link into a non-transparent link.
Accordingly, it is a desire of the present invention to provide for methods and devices for improving optical cross-connections and nodes.
It is also a desire of the present invention to provide for methods and devices that reduces the cost of ULR networks.
It is yet a further desire of the present invention to provide for methods and devices that increases the transparency of ULR networks.
Further desires will be apparent from the drawings, detailed description of the invention and claims which follow.